The present invention relates to a method for direct airborne electromagnetic prospecting of hydrocarbons; for example, oil and gas deposits. Specifically, it relates to a method wherein electromagnetic field induced polarization measurements are made by measuring the change in phase and amplitude of three orthogonal electromagnetic components H.sub.x, H.sub.y, H.sub.z at many different combinations of electromagnetic transmitter characteristics. The measured results are then electronically processed directly into hydrocarbon occurrence probability levels on the basis of pattern recognition theory.